In wireless communication networks, a user uses a UE (User Equipment) for communicating with a RAN (Radio Access Network). With the emergence of available services, the users increase their data traffic and requests more efficient UE:s. One type of more efficient UE which has been developed is multiple bearers UE, i.e. UE:s applying more than one radio bearers each in their communication with the wireless communication network node.
In this description, the term “User Equipment” will be used to denote any suitable communication terminal adapted to communicate with a radio base station. A UE, may be implemented as a mobile phone, a PDA (Personal Digital Assistant), a handheld computer, a laptop computer, etc. A “radio base station” may be implemented as a NodeB, an eNodeB, a repeater, etc.
“Scheduling” is a process for controlling which UE:s that shall be allowed to communicating data with a base station in a radio access network. This description relates to communication of data in uplink and the described processes will be in accordance with communication of data in uplink. The scheduler is present in a radio base station and in uplink the scheduler receives requests to transmit from the UE:s which the UE:s are communicating with. In response to the requests, and based on parameters as: the amount of data to be transmitted in uplink, the available capacity for uplink data, etc., the scheduler allocates communication capacity for communication of data in uplink and distributes scheduling grants to the UE:s accordingly. When having received a scheduling grant, the UE transmits data in uplink according to the scheduling grant. The UE:s are also capable of notifying the scheduler of their needs for communication resources in uplink, and may indicate whether they are happy or not with the assigned grants or with buffer status. In WCDMA networks, for instance, a specific so called “happy-bit” may be set when requesting to be scheduled, for indicating that the UE requires to transmit data in uplink at a higher data rate, i.e. a UE requires to be scheduled more frequently, or at an increased data rate. In downlink the situation is different, the scheduling is there initiated by the radio access network and not by the UE, and will not be further discussed in this description.
The term “Radio Bearer” is used throughout this description to denote radio resources being set up and applied of a UE for communicating data between the UE and a RAN. The term “Radio Access Bearer”, also abbreviated as RAB is a term denoting a logic communication resource between the UE and a core network.
With reference to FIG. 1, a scenario where a multi bearer UE transmits uplink data to a radio access network will now be described.
A UE 100 communicates data with a radio access network 102. The radio access network comprises a radio base station 104 and a radio network controller 106, and the radio access network 102 is connected to a core network 108. The UE 100 is a multiple bearer UE and applies two radio bearers B1, B2 for the communication. The UE 100 which wants to transmit data in uplink, requests a scheduler (not shown) in the radio access network 102 to be scheduled to transmit data. When scheduling, the scheduler decides which UE to be granted to transmit data in uplink. The scheduler bases its decision on parameters as: available communication capacity for uplink, the transmission needs in uplink and required QoS (Quality of Service) for all UE:s.
Commonly, in wireless communication networks, there are limited resources for communicating data, especially in uplink. Therefore, the operators of wireless communication networks assign the radio bearers various priorities, e.g. a UE may have one prioritised radio bearer and one non-prioritised radio bearer. Thereby, the operators are enabled to reserve prioritised radio bearers for desired services. For instance, the prioritised radio bearers will be reserved for voice and video services and the low-prioritised radio bearers will be used for less desired services, or services which not require real-time characteristics, e.g. SMS (Short Message Service), file downloading, peer-to-peer networking, etc. To enable a scheduler to perform allocation of communication resources, scheduling information is communicated between the UE:s and the radio access network. An accurate scheduling requires a substantial amount of scheduling information, which causes increased signalling load on the air interface.
There is a need to fairly and accurate allocate available communication resources to the UE:s in a wireless communication network, without increasing the amount of scheduling information.